Chromiferous monoazo-dyestuffs



'Patented June 3, 1952 u tions such that the radical A1 ixSLSDlit off. `20 slderatmn'efor example' the f in which1-R1`-l-represents anammaticiradiealzO-the benzeneSeriesireefirm Sulfur: fin. whichthepsube StimentsrNHz: Q-#Alana- ''.Q-Az1areymthe 1 2--yand I-reustonsj respectively; and; il1-aridEA? each repres'entv-an 'alkyl grourmwih afhydrbxy: naphthalenemonoor zdif-,sulfonclacid capable of couplingm o rtho'eposition toy-th'efhydloyl group.

S-nce `in 2 -hydrxynaphthaflenes couplir'lgstakes i fivh@sO edvantegeus1y-nduted:man:alkaimemedlylm, with-regard toya :naphthalene radcalafisfunderf- 40 'fer-v-example'gneendered a'lkelfne WIW-eet??? stoodto meangtheY posit-10ndl :2 :(orf 3:4; 5 :6;A 71:8) Qalbonater- If lfdesilfed; Y the'couplmgmayfb l11011- only, but not the position 2 :3 (or 61:77)'. ducted in "the presenceefeSuitmeeeweteeeh In the amines of the above forgriula serving as f diam-components the 'aclcal R1 Iay be free from Y further sub s t ituent` l`may conta further substituents, which" 'muet be fe lfiomV sulfur. As such substituents` therecome into cnsideraton, for example, nito, 4ai;ylamiiflo aldalkyl groups or halogen atoms such as fluorinevobromine and Og-A1- especially chlorine. v l

"ljhftw 'l-kyleifoupjiga-'A omo f1 u `ev chlorine atom. For example, monoazo-dyestuis of the formula -able chromiferous compounds being obtained with those dyestus which contain two sulfonic acid groups in the naphthalene radical, for example,

those of the formula Ho soaH O-Ai VHOiS- or more especially those of the formula HO O-Ai The monoazo-dyestus used as starting materials may, if desired, be isolated from the coupling mixture and freed from impurities. In general, however, the coupling mixture as a whole and without any intermediate separation may be used for the treatment with the agent yielding chromium, As a rule it is necessary in this case, before carrying out the reaction with the agent yielding chromium, to adjust the pH .of the coupling mixture to a value favorable for the reaction, that is to say, to render it weakly acidwith a mineral acid.

As agents yielding chromium there come into consideration above all salts of trivalent chromium, such as chromium iluoride, chromium sulfate, chromium acetate and chromium formate. The treatment with the agent yielding chromium is carried out under conditions such that the alkyl vgroup'li 'is'split off. This splitting off with the simultaneous formation of the complex chromium compound may be conducted by a method in -itself known, by carrying out the treatment with theagent yielding chromium, for example,

Y with chromium formate or chromium sulfate in an aqueous medium, advantageously a mineral acid medium, under pressure at a raised temperature, for example, a temperature ranging from 110 C. to 140 C.

The chromiferous dyestuffs obtainable by the invention are new. They are complex chromium compounds of monoazo dyestuis of the general formula H Ho 1N=N 9 .-42 y in which R1 represents an aromatic radical of the benzene series-free from sulfur, in which the substituents -N-:N-, OII and Oe-A2 are -in theY l-, 24- and -positions respectivelyf A2 represents an alkyl group, and R2 represents a naphthalene radical which contains at least one and at the most two sulfonic acid groups and is bound to the azo linkage in ortho-position to the hydroxyl group.

These products are suitable above all for dyeing materials of animal origin, such as silk, leather and especially wool, and are also suitable for dyeing artificial bers of superpolyamides or superpolyurethanes. The dyeings obtainable therewith are distinguished by good fastness to Awashing, fulling and light. Furthermore, these new products are in general distinguished from the known products of similar constitution principally in that they yield level dyeings of especially pure tints, which retain their purity when viewed in articial light.

The following examples illustrate the invention, the parts and percentages being by weight:

Example 1 15.3 parts of 2:5-dimethoxy-1-aminobenzene are diazotized in the usual manner with '7 parts of sodium nitrite in the presence of 30y parts of hydrochloric acid of 30 per cent. strength. The solution is filtered, and the ltered solution of the diazo compound is run into a solution cooled to 10 C. of 23 parts of Z-hydroxynaphthalene- 4-sulfonic acid and 40 parts of anhydrous sodium carbonate in 400 parts of water, while stirring well. The greater part of the dyestui formed precipitates, and is separated by filtration. It corresponds to the formula O-CHa OH When dry, it is a dark colored substance which dissolves in dilute sodium carbonate solution with a Bordeaux red coloration and in concentratedV sulfuric acid with a blue coloration, and dyes wool from an acid bath Bordeaux red tints.

This dyestui can be converted, advantageously without preliminary drying, into its complex chromium compound. For this purpose the dyestuil paste obtained as described above is stirred with 1000 parts of hot water and suicient sulfuric acid of 10 per cent. strength to produce a weakly mineral acid reaction. After the addition of a quantity-'of chromium sulfate [Crz(SO4)3l containing 5.7 parts of Cr, the reaction mixture is heated in a lead-lined autoclave fitted with stirring mechanism at -130 C. and stirred for 20 hours at that temperature. The greater part of the chromium compound formed precipitates. After allowing the mixture to cool to room temperature the chromium compound which isY a chromium compound of the monoazo dyestuff of the formula (IDH OHv

is separated by iiltration and washed with sodium aracoupled,with.,23 parts.ofiahydroxynaohtha- V.fZQrrdyestul..istchromedtin.themannr described in the rst paragraph of this examblaa' Achromi- IerOus dyestui .is .obtained .which .dyes ,woolj from aV sulfuric acid bath reddish :blue tints. A

Example 2 18.8 parts of 2:5-dimethoxy-lamino4chloro benzene are diazotized'in theiusual manner with l parts of sodium nitrite` in lthe presence of 30 parts of hydrochloric acidof 30per cent. strength. The resulting clear solution of the diazo compound is run, While stirring well into a solution -l'enefizSedi-sulfonlc:acid. andz30; parts ofianhy- -dro.usssbdiurncaafrlconatev .in A00 :parts of :.water. f-Thdj-graterfpartof thegdyestuffiformed precipitates. .fIt corresponds; to; the :formula When dry it is a dark colored substance which dissolves in water and in dilute sodium carbonate solution with a ruby red coloration and in concentrated sulfuric acidWith a blue coloration,

The; dyestuft-.canz--be :converted intoitscomplex -clfiromiumf.compoundwithoutintermediateiseparation For-this purpose the. coupling Imixture obtained as described above is diluted WithnZO-G nartsfof 'fwaterf andvsufcient fsulfuridacidi of; l o per cent. strength tofgive'aiu/Eea'klyy mineral-.acid reaction. After the addition of a quantity of chromium su1fate-,;[Cr2(SO4)3l containing 5.7 parts of Cr, the reaction ,mixture is heated in a lead-lined autoclave ttedwith stirring mechanism at 120-125 C. and stirred for 15 hours at that temperature. The greater part of the resulting chromium compound-precipitates After allowing the whole to cool to room temperature -thefcompoundwhic'h -is aA chromium LAcompound Tfof is separated-.by filtering-.andi dried. In this state it is a dark colored substance Which dissolves in anddyesswoolffroman acidfbathbluish-:redz tints.

of alkalli hydroxidesfwithaasrubyfredicoloraftion,

' 153 #parts of 1:2 idimethoxy-1-aminobenzene .are-diazotized vin the iusualsmanner. withfifpants `ofiisodiu'm'anitr-itei inithe .presence :of-;47@ipar.ts .of sulfuric acid of 38 per..cent.\.strength. "f'lhesolution is ltered, andg. t he ltered solution of the diazo compound isrun into a solution cooled to 10 C. of flgparts of 1,-hydroxynaphthalene-3:8- disulfonic acid andfl parts of; anhydrous sodium carbonate in l100 parts of Waterwhile stirring Well. The great/appart of the--fdyestuff formed which corresponds to the formula Jolcpitatesl .and .is-separated byiltration after the... addition. ofssodium, chloride. ...When drydt isa.da`rk. red .substance which .dissolves .indilute sodium ,carbonate solution .wl-ithv. .a red, coloration and .in .concentrated...sulfuric. acid..,w.`ith., a .blue .coloration .and dyes.. Wool from anacidlbath ,red .tints.

The f dyestuil". can .be converted..advantageously -Withoutprelimnarv dlylflaintov its .complex chromium compound. ,Forthispurpose .theore- -stuffs)aste vvobtained as described. above is .stirred `.with .1000y parts .of .hot .water v.and suiicientsulfur-icracid of 1Q-percent.,strength .to giyea ,weakly., mineralacid reaction. After thetaldditiontofa .quantity of vloasie..chromium sulfate (CizQlLSQ-i) .containing 5.7 parts ofV Cr, the .-reaction..inixture .isheated atv 115-.125y C..i n a .leadrlined autoclave -fitted .with stirring mechanism andfsitirred'ior llhours at that temperature. ."Ihegreateripart ofthe chromium compoundormed precipitates. The precipitation can be completed by the addition of sodium chloride. Thedyestuff which is a chromium compound of thefrnonoazo-dyestuf of the formula -isfseparated by-llltration after coolingitlieemlxture "'to'eroomftemperature. '-*Inthefdry-state-itfisada-rk fcoloredepowder-whichdissolvessinfdllute:sodium carbonate solution-With a1redblue=o1oratiorrand in concentrated sulfuric acid with a ivioletered lcolorationfand fdyes'- WoolfromA a vsulfuric acid `bath-very-level, fast; blue= tints-f-Which have-practicallyfthe?sarneffbueh-When Lviewed ineartifioial -light1as-in 'dafylight.

Achromiferousidyestuff having/,similar properwater with a blue coloration;sinadiluted solutions 'ftieseis obtained by-'using=, insteadfoffldpartsiof 2:5-dimethoxy-l-aminobenzene; 18.8 parts of 2:5 dimethoxy- 4 -chloro-l-aminobenzene Vand otherwise proceeding in the manner described above.

Exam-ple 4 19.8 parts of 2:5-dimethoxy-4-nitro-l-aminobenzene are diazotized in the usual manner with 7 parts of sodiumrnitrite in the presence of 115 parts of hydrochloric acid of 30 per cent. strength. The solution is i'lltere'd, and the filtered solution of the diazo compound is run, While stirring well into a solution cooled to 10 C`. of 23 parts of 2- hydroxynaphthalene-4-sulfonic acid and 100 parts of anhydrous sodium carbonate in 800 parts of water. The greater part of the dyestuff formed precipitates and is separated by filtration. It corresponds to the formula O--CHs HCI) (IJ-CHS When dry it is a dark red substance which dissolves in dilute sodium carbonate solution with a Bordeaux red coloration and in concentrated sulfuric acid with a blue coloration, and dyes wool from an acid bath red tints.

The dyestui can be converted, advantageously without preliminary drying, into its complex chromium compound. For this purpose the dyestuff paste obtained as described above is stirred with 1000 parts oi hot water and suicient sulfuric acid of 10 per cent. strength to produce a Vweakly mineral acid reaction. After the addition of a quantity of chromium sulfate [Cr2(SO4)3l containing 5.7 parts of Cr, the reaction mixture is heated at 12o-125 C. in a lead-lined autoclave fitted with stirring mechanism and stirred for 20 hours at that temperature. The greater part of the chromium compound formed precipitates. It is separated by filtering while hot, and washed with hot water until the initially yellow filtrate has a pure bluish tint. The lter residue is heated at 60 C. with 200 parts of hot water and 15 parts of sodium hydroxide solutionl of 30 per cent. strength, whereby the chromiferous dyestuif dissolves. The dyestui solution is filtered and the complex chromium compound which is a complex chromium compound of the monoazo-dyestuff of the formula -CHa Y properties is obtained by using instead of the 2- hydroxynaphthalene-4-su1fonic acid, the same quantity of 2-hydroxynaphtha1ene-6-sulfonic acid. carrying out the chroming operation in the `autoclave for 25 hours at 125-130" C. andother- Wise proceeding in the manner'descrlbed above. The dyestuff so obtained is a dark powder which dissolves in dilute sodium carbonate solution with a blue coloration and in concentrated sulfuric acid with a Bordeaux r-ed coloration and dyes wool from a sulfuric acid bath very level fast grey-blue tints.

Example 5 parts of well wetted wool are entered at 40 C. into a dyebath which contains 2 parts of the chromiferous dyestui obtainable as described in the rst and second paragraphs of Example 2, 40 parts of sulfuric acid of 10 per cent. strength and 3000 parts of Water. The bath is slowly heated to the boil. After boiling for 1A; hour a further 40 parts of sulfuric acid of l0 per cent. strength are added and dyeing is carried on for 11/2 hours at the boil. The wool is then rinsed in cold water and dried. It is dyed a pure blue tint.

Having thus described the invention, what is claimed is:

1. A complex chromium compound of a monoazo-dyestui of the formula in which R2 represents a naphthalene radical which contains at least one and at most two sulfonic acid groups and which is bound to the 'azolinkage in ortho-position to the hydroxyl group and X represents a member selected from the group consisting of a hydrogen atom and a halogen atom.

2. A complex chromium compound of a monoazo-dyestui of the formula in which Rz represents a naphthalene radical which contains at least one and at the most two sulfonic acid groups and which is bound to the azo-group in ortho-position to the hydroxyl group.

3. A complex chromium compound of a monoazc-dyestuff of the formula -CHa in which R2 represents a naphthalene radical which contains at least one and at most two s ulfonic acid groups and which is bound to the azo= group in ortho-position to the hydroxyl group. 4. A complex chromium compound of the monoazo-dyestui of the formula OH Hfl) Cl- H098- SOsH -CHs 5. complex chromium compound of the monoazo-dyestuff ofthe formula.

8. A complex chromium compound of the 10 monoazo-dyestui of the formula on on A Number WILLY WIDMER. 2g JAKOB BRAssEL.

The following references are of record in the le of this patent:

UNITED STATES PATENTS Name Date Geldermann Dec. 12, 1911 Herzberg et a1 Sept. 1'1, 1912 Knecht July 18, 1944 Anderson May 14, 1946 Straub et al Oct. 26, 1948 FOREIGN PATENTS Country Date Switzerland Dec. 1, 1950 

1. A COMPLEX CHROMIUM COMPOUND OF A MONOAZO-DYESTUFF OF THE FORMULA 